function [T new_x]=normalize(x)
std_new_x=std(x');
center_new_x=mean(x');
center_new_x=center_new_x./std_new_x;
T=[1/std_new_x(1) 0 -center_new_x(1);
    0 1/std_new_x(2) -center_new_x(2);
    0 0 1];
new_x=T*x;